TWI427956B - Method and base station for transmitting data on reduced transmission time interval(rtti) timeslot pair - Google Patents

Description

Method for transmitting data on a slot pair when reducing the transmission time interval (RTTI) Base station

This application relates to wireless communications.

The Global System for Mobile Communications (GSM) Standard Release 7 (R7) introduces several features that improve the throughput of the uplink (UL) and downlink (DL) and reduce transmission delay. Among these features, GSM R7 introduces Enhanced General Packet Radio Service 2 (EGPRS-2) to improve DL and UL throughput. The improvement in EGPRS-2 throughput in the DL is called the REDHOT (RH) feature, and the UL improvement is called the HUGE feature. EGPRS-2 DL and REDHOT are synonymous.

In addition to traditional enhanced general-purpose packet radio services (EGPRS) based on Gaussian Minimum Shift Keying (GMSK) (MCS-1 to MCS-4) and 8-Phase Shift Keying (8PSK) Modulation (MCS-5 to MCS-9) In addition to the Modulation and Coding Scheme (MCS), REDHOT also uses Quadrature PSK (QPSK), 16 Quadrature Amplitude Modulation (16QAM), and 32QAM modulation. Another technique for increasing throughput is to use Turbo coding (as opposed to convolutional coding of EGPRS). Furthermore, higher symbol rate operation (conventional 1.2x symbol rate) is another improvement.

A network and/or a wireless transmit/receive unit (WTRU) supporting REDHOT may implement REDHOT Level A (RH-A) or REDHOT Level B (RH-B). While RH-B WTRUs will achieve maximum throughput gain by using a corpus of performance improvement features defined for REDHOT, a selected subset of RH-A WTRUs implementing improved techniques will also reach Beyond the net improvement of traditional EGPRS. The RH-A solution will also be easier to implement than the full RH-B implementation.

In particular, RH-A will implement eight (8) new MCSs using 8PSK, 16QAM, and 32QAM modulation. These are referred to as downlink level AMCS (DAS)-5 to DAS-12. RH-B will implement another set of eight (8) new MCSs based on QPSK, 16QAM, and 32QAM modulation. These are referred to as downlink levels B MCS(DBS)-5 to DBS-12. Unlike traditional EGPRS, both RH-A and RH-B use Turbo coding for the data portion of the radio block. For link adaptation purposes, both RH-A and RH-B WTRUs will reuse legacy EGPRS MCS-1 through MCS-4 (both based on GMSK modulation). In addition, RH-A will reuse traditional EGPRS MCS-7 and MCS-8 for link adaptation, while RH-B will reuse legacy EGPRS MCS-8 and RH-A DAS-6 for link adaptation. , DAS-9 and DAS-11. Therefore, the RH-A WTRU will support MCS-1 to MCS-4, MCS-7 to MCS-8, and DAS-5 to DAS-12, while the RH-B WTRU will support MCS-1 to MCS-4, MCS- 8, DAS-6, DAS-9, DAS-11, and DBS-5 to DBS-12. However, the RH-A WTRU will exclusively operate at the legacy (low) EGPRS symbol rate (LSR) while the RH-B WTRU is capable of operating at a higher symbol rate (HSR). The RH-B WTRU needs to implement functionality according to the RH-A and RH-B specifications. However, when the RH-B WTRU is configured to receive packet data, it will operate in legacy EGPRS mode, RH-A or RH-B mode.

Traditional EGPRS and new types of RH-A and RH-B WTRUs can operate together on the same time slot, traditional EGPRS uplink status flag The principle of (USF) operation and PAN decoding may be combined with the GSM R7 Delay Reduction (LATRED) feature (with specific limitations).

The RH-A and RH-B WTRUs need to decode the USF of the received radio block on the assigned one or more time slots. In addition, for reasons of forward compatibility, the RH-B WTRU needs to implement functionality to allow the WTRU to distinguish between RH-A and RH-B modulation bursts (DAS-x modulation and coding schemes) Relative to DBS-x). Since the resources for RH-A and RH-B mobile stations (e.g., time slots) can be easily brought together, there is a need in order to increase the use of shared channels and reduce the labor intensity of the operator's radio planning.

The USF consists of three (3) information bits encoded as variable number bits according to the coding scheme (CS) used. In GPRS, in order to decode the USF, the WTRU first decodes the stealing flag, which indicates whether GPRS CS-1, CS-2, CS-3 or CS-4 is used. There is exactly one (1) stealing flag before the training sequence in each burst, and there is one (1) stealing flag after the training sequence in each burst, so that there are a total of eight in the radio block (8). ) a misappropriation flag.

GPRS sets these stealing flags according to the following rules: q(0), q(1), ..., q(7) = all 1s indicate the coding scheme CS-1; q(0), q(1),. ..,q(7)=1,1,0,0,1,0,0,0 denotes the coding scheme CS-2;q(0),q(1),...,q(7)=0 , 0, 1, 0, 0, 0, 0, 1 represents the coding scheme CS-3; and q (0), q (1), ..., q (7) = 0, 0, 0, 1, 0 1,1,0 represents the coding scheme CS-4.

In the case of GPRS CS-1 to CS-3, USF consists of convolutional code and Radio Link Control (RLC)/Media Access Control (MAC) headers and data. The remainder of the section is encoded together. Therefore, decoding of the entire radio block (4 bursts) requires USF. In the case of CS-4, however, three USF information bits are block coded into 12 encoded bits and mapped separately from the RLC/MAC header and data portions of the radio block. The USF can be extracted without decoding the entire radio block.

In the case of GPRS CS-4, the 12 encoded USF bits are included in the following symbol locations distributed through the data portion of the burst: {0 in the first burst of the radio block (1), 50,100}; (2) {34,84,98} in the second burst; (3) {18,68,82} in the third burst; and (4) fourth (final) {2,52,66} in the hair.

Figure 3 shows the burst map of the USF sent in 20ms. The encoded USF bits are placed at different symbol locations depending on the bursts in the radio block. Since all bursts are GMSK modulations (1 bit per symbol), the symbol position is equivalent to the bit position. Because these bit locations are known and fixed, there is no need to decode the entire RLC/MAC header and the entire data portion of the radio block in order to read the USF (unlike the CS-1 to CS-3 coding scheme). However, the equalization of the data portion is still a problem because inter-symbol interference (ISI) from the data symbols distorts the USF symbols contained therein.

A WTRU with EGPRS capability needs to decode the USF of the EGPRS radio block. The EGPRS radio block can be either GMSK modulation (MCS-1 to MCS-4) or 8PSK modulation (MCS-5 to MCS-9). although Although the original GPRS WTRU cannot receive 8PSK modulated blocks, the solution for the GMSK modulated EGPRS radio block is to encode the USF and place the GMSK modulated in exactly the same way as defined by the traditional GPRS coding scheme CS-4. 12 block encoded USF bits of the EGPRS radio block. Thus the GPRS WTRU is convinced that the CS-4 radio block is placed in the exact same location as in the legacy GPRS radio block by placing the stealing bits in the GMSK modulated EGPRS radio block and setting these stealing flags for The code word of CS-4 is received.

GPRS CS-4 and thus implicit EGPRS MCS-1 to MCS-4 are indicated by setting the stealing bit to 00010110. Thus, the GPRS WTRU will successfully (unless the radio conditions are too bad) decode the USF while believing that the block is a CS-4 radio block. Next, the GPRS WTRU will attempt to decode the rest of the EGPRS radio block as a CS-4 block and fail (due to a Cyclic Redundancy Check (CRC) failure). The EGPRS WTRU will also read the legacy stealing bit, but for the EGPRS WTRU, the CS-4 stealing bit codeword means that the EGPRS radio block has been transmitted (MCS-1 to MCS-4). Therefore, assuming that the GPRS WTRU performs decoding of the USF, and since the USF is placed in the correct location (same location as CS-4), this will succeed. Subsequently, in order to determine which modulation and coding scheme (eg, MCS-1 to MCS-4) has been used, the EGPRS WTRU decodes the RLC/MAC header and looks at the coding and puncturing scheme (CPS) field, and decodes the radio. The rest of the block. If the radio block is indeed a CS-4 radio block, then the latter part will fail (due to a CRC failure during RLC/MAC header decoding).

When using EGPRS MCS-5 to MCS-9 (all 8PSK), the 3-bit USF is block coded to thirty-six (36) bits, and if CS-4 and MCS-1 to MCS-4 Medium is handled independently of the RLC/MAC header and the data portion of the radio block. However, unlike CS-4 and MCS-1 to MCS-4, these thirty-six (36)-block encoded USF bits are mapped to exactly the same bit position in each of the four bursts that make up the radio block. Collections {150, 151, 168-169, 171-172, 177, 178 and 195}.

Figure 4 shows the bursts used for MCS-5 and MCS-6 mapping before or after bit swapping. Figure 5 shows the bursts used for MCS-7, MCS-8, and MCS-9 mapping before or after bit swapping.

The WTRU modulates the GMSK modulated radio blocks (CS-4 and MCS-1 to MCS-4) and the 8PSK modulated radio blocks (MCS-5 to MCS- by detecting the correct phase rotation on the burst training sequence). 9) Make a distinction between. Next, in order to retrieve the USF symbols/bits from the correct location, the WTRU needs to properly configure the decoder because the USF bits mapped in the GMSK bursts (MCS-1 to MCS-4) are different from Mapping used in 8PSK bursts (MCS-5 to MCS-9).

In the GSM Enhanced Data Rate of the Global Evolution (Edge) Radio Access Network (GERAN), the USF is encoded in a similar manner to the new 8PSK EGPRS MCS-5 to MCS-9 based on the DAS-5 to DAS-7 scheme. to realise. This means that the three USF bits are block coded into 36 full USF coded bits and mapped to the exact same set of bit positions of each of the four bursts that make up the radio block {150, 151, 168-169, 171-172, 177, 178 and 195}, as for the traditional EGPRS MCS-5 to Description of the MCS-9 situation.

For the new 16QAM based on the DAS-8 and DAS-9 schemes, the 3 USF bit blocks are encoded as 48 total USF coded bits. These are then mapped to bit positions 232 through 243 in the bursts of the four bursts that make up the radio block. This means that the USF is mapped to three (3) 16QAM symbols immediately following the training sequence.

For the new 32QAM based on the DAS-10 to DAS-12 scheme, 3 USF bits are encoded as 60 total USF channel coding bits. These are then mapped to bit positions 290 through 304 in the bursts of the four (4) bursts that make up the radio block. This means that the USF is mapped to three (3) 32QAM symbols immediately following the training sequence.

For all new RH-A schemes DAS-5 to DAS-12, the location of the bit containing the channel-coded USF bit is fixed and accurate with respect to all four (4) bursts that make up the radio block. The same ground. However, there are 3 different types of USF code tables to be supported and there are 2 different USF location sets in the REDHOT burst. In the RH-A WTRU, the USF encoding is implemented in the manner described in CS-4/MCS-1 to MCS-4, and thus the RH-A WTRU must also support the legacy EGPRS MCS-1 to MCS on the REDHOT time slot. -4. For this reason, the RH-A WTRU must support a total of 4 types of USF code tables and 3 different USF location sets. Also note that the traditional MCS-1 to MCS-4, and DAS-5 to DAS-7 USF captures still require equalization of the data portion of the burst because the USF coded bits are included in these bursts. intermediate. This is not required for DAS-8 to DAS-12, and only needs to be from the training sequence. The column has an ISI equalization because the 3 USF symbols just trail the midamble before the data portion begins.

Since the RH-B WTRU must be able to retrieve the USF, even when the burst uses any of the new RH-A DAS-5 to DAS-12 schemes for transmission, the number of USF code tables and the USF bit location mapping table are further Increase as described below.

The new type of RH-B burst (DBS-5 to DBS-12) places the USF into the 4 symbols immediately following the training sequence. This allows the USF bit to be fetched by the RH-B WTRU without requiring the WTRU to equalize the entire burst. Similar to RH-A, since the modulation type detection and channel estimation based on the training sequence are always required at first, the USF is placed adjacent to the training sequence. Thus, the RH-B WTRU only needs to detect the training sequence and neighboring USF symbols. The USF is placed after the intermediate code. The reason for this is that typical channel burst responses have only relatively small precursors (eg, similar to several nanoseconds), but have larger post cursors (eg, similar to several microseconds) . When the USF follows the training sequence, the most critical ISI on the USF symbol will be generated directly by the training sequence and the USF symbol itself. Therefore, there is no need to balance the payload symbols.

In GERAN, four (4) USF symbols are used per RH-B burst (and thus 4x4 = 16 total symbols per radio block). It translates to 16x2=32, 16x4=64, and 16x5=80 bit positions, respectively, from the RLC/MAC header, the enqueried positive acknowledgement (ACK)/negative acknowledgement (NACK), and if present, the PAN, And QPSK (DBS-5-6), 16QAM (DBS-7 to DBS-9) and 32QAM (DBS-10) To the DBS-12) section of the data section of the modulation. Since QPSK is part of RH-B, the principle must act on four quaternary symbols per burst. Therefore, basically mapping the USF channel coding bits to symbols will use QPSK and then extend to the 16-QAM and 32-QAM burst formats by using only the constellation points of the four corners other than the 16 or 32 constellation points.

For all new RH-B burst formats DBS-5 to DBS-12, the USF of three (3) bits is always encoded as a 16-bit long encoded USF. For each burst, four (4) USF coded bits are mapped to four (4) symbols immediately following the training sequence. The first two (2) USF coded bits are mapped to the first symbol and the second symbol contains a copy of the phase rotation of the first symbol. The same principle applies to the second set of two (2) USF encoded bits mapped to the third and fourth symbols. The mapping of RH-B bursts to four (4) symbols is shown in Figure 6.

In particular, the RH-B WTRU must perform modulation type detection of GMSK, 8PSK, QPSK, 16QAM, and 32QAM. This is done by rotating the version correlation with the phase of the intermediate code depending on the modulation type used. Furthermore, the correlation for 16QAM and 32QAM must be done at the traditional symbol rate and the new higher symbol rate.

Next, the WTRU must reconfigure its receiver based on the detected modulation type. For example, if GMSK (MCS-1 to MCS-4) is detected, the WTRU retrieves USF from the first set of locations (as described above). If 8PSK (DAS-5 to DAS-7) is detected, the WTRU retrieves the USF from the second set of locations as described above and employs a different mapping table. In both cases, the WTRU equalizes the portion of the burst of data to process the USF. If detected 16QAM or 32QAM, the WTRU still processes three (3) or four (4) symbols at the third set of USF locations depending on whether HSR (RH-B) or LSR (RH-A) is detected. In these latter cases, the WTRU equalizes any portion of the data in the burst because the USF symbol follows the midamble. For bursts of the GMSK and 8PSK burst types, the USF is located in the middle of the data portion before or after the midamble, so the entire burst needs to be equalized to capture the USF. For QPSK/16QAM/32QAM MCS, the USF follows the midamble and only the interference from the midamble needs to be removed before the USF symbol is retrieved.

Because the RH-B WTRU must implement all of the functionality of the RH-A WTRU, an effective level of complexity is required. The WTRU may discard the received block if it cannot receive the data or control block transmitted in each radio block on one or more time slots it is assigned to, and once it determines that the block is to be used by another WTRU. For the remainder, the WTRU still needs to retrieve and process the USF field on any such received block, even though the USF field may be addressed to another WTRU. Another disadvantage is that this approach results in significant WTRU processing delays in the receiver. Yet another problem is that the RH-A WTRU needs to balance all or at least one valid segment of the data portion of the burst dedicated to the USF, because EGPRS MCS-1 to MCS-4 and DAS-5 to DAS-7 Map the USF symbol somewhere to the middle of the burst.

Therefore, a method for reducing the USF decoding complexity of an RH WTRU is highly desirable.

The additional complexity of USF decoding in EGPRS2 is due to the combination of shrinkage Operation performed with reduced transmission time interval (RTTI) transport format provided by the GSM Release 7 LATRED feature. Prior to Release 7, legacy EGPRS was only offered with the possibility of using the traditional transmission format of Basic Transmission Time Interval (BTTI). A typical BTTI transmission includes four (4) bursts that make up a conventional EGPRS radio block that is transmitted on the same assigned time slot of each frame on four (4) consecutive frames. For example, if the WTRU is allocated slot (TS) #3, the WTRU will retrieve from TS#3 in GSM frame N+1 by extracting burst #1 from TS#3 in GSM frame N. Congfa #2, extracting Congfa #3 from TS#3 in GSM frame N+2, and finally extracting C## from TS#3 in GSM frame N+4 to receive the entire radio block . Therefore any transmission of the entire radio block will cost 4 frames multiplied by 4.615 milliseconds of GSM frame duration, or roughly 20 milliseconds. Note that when the WTRU is assigned more than one TS for reception of data, any of these time slots includes separate radio blocks received over a duration of 20 milliseconds. The GSM standard defines timing frame rules that specify exactly when a radio block can begin (eg, which GSM frame includes burst #1). GSM Release 7 provides an additional possibility to use the RTTI transport format, where one time slot pair in the GSM frame N includes the first two (2) bursts, and the GSM frame N+1 includes four radio blocks. (4) The second group of two (2) bursts in the total burst. Therefore, the transmission using RTTI only takes 2 frames multiplied by 4.615 milliseconds, or roughly 10 milliseconds. RTTI operation is possible for EGPRS and EGPRS2. At any given time slot, the BTTI and RTTI WTRUs can be multiplexed while still allowing the USF to be transmitted to the BTTI WTRU using the RTTI radio block. The possibility and vice versa. The GSM standard also allows for the possibility of exclusively allocating time slots to BTTI-only WTRUs, or exclusively to RTTI-only WTRUs. For legacy EGPRS devices, the reduced-delay (RL)-EGPRS WTRU's RTTI transmissions that are multiplexed to the shared time slot must take into account the legacy USF format and the corresponding legacy BTTI EGPRS WTRU's stealing flag settings. Therefore, in order not to affect the USF decoding capability of a conventional BTTI EGPRS WTRU, any two RTTI radio blocks transmitted to a RL-EGPRS WTRU in a legacy BTTI time interval must select exactly the same modulation type (GMSK/GMSK or 8PSK/). 8PSK).

However, in the case of EGPRS2 RH-A and/or RH-B WTRUs, in principle this limitation of employing exactly the same type of modulation does not exist. If this restriction does not exist, this allows the EGPRS2 system to achieve higher throughput because it can schedule the appropriate modulation and coding scheme (MCS/) independently for the first and second RTTI WTRUs on the same BTTI interval. DAS/DBS). In particular, the GMSK MCS on the first interval does not force the network to transmit GMSK MCS on the second RTTI interval, such as is required in the RTTI/BTTI operation of a legacy EGPRS WTRU, and thus reduces throughput, because The EGPRS2 WTRU can be designed to handle this situation properly (using the correct decoding scheme). However, the result is that the BTTI EGPRS2 WTRU is able to perceive a wide range of possible USF combinations using the first modulation on the first set of two bursts and the burst on the other of the second set of two bursts. Therefore, the complexity of decoding is greatly increased, even exceeding the current state of the field. Therefore, the EGPRS2 WTRU is degraded (processing time is increased) because it The first modulation type needs to be detected on the first RTTI interval, the corresponding first group of USF locations and the corresponding USF coding table are determined, and then the second modulation type is determined on the second RTTI interval, and the second group of USF locations and The respective USF code table. As described above, because the USF location varies with each modulation scheme (at least three (3) different groups), the additional RTTI/BTTI mode of operation associated with the transmission of the EGPRS2 radio block results in an undesirably large amount of A combination of USF decoding attempts. In some cases (eg GMSK), due to modulation variations between the first or second RTTI intervals, and because of the corresponding USF coding table for each modulation and coding (eg MCS/DAS/DBS) scheme (multiple There are five (5) code tables), so there are more combinations of USF decoding attempts.

Therefore, methods are sought to simplify the processing complexity associated with WTRU USF decoding and achieve higher throughput by employing a mixed-modulation RTTI/BTTI interval with EGPRS2 transmission.

A method and apparatus for allowing reliable and low complexity decoding of EGPRS2 communication bursts when RTTI and BTTI devices operate on one or more of the same time slots. The various configurations for Uplink State Flag (USF) mapping use the adjustable bit swapping of some or all of the USF channel encoding bits in the communication burst. Adjustable use of the symbol mapping phase in the transmitter or receiver is also allowed to allow for higher throughput and/or reduced complexity configuration. Allowable mapping rules are known to the receiver and transmitter, and thus reduce the complexity of decoding the information. In order to increase the throughput of EGPRS2 communication bursts, different modulation types of RTTI transmissions are introduced or EGPRS/EGPRS2 modulation and coding scheme during BTTI interval, which allows reliable USF decoding and reduced decoder complexity.

"Wireless transmit/receive unit (WTRU)" as referred to below includes, but is not limited to, user equipment (UE), mobile station, fixed or mobile subscriber unit, pager, cellular telephone, personal digital assistant (PDA), computer or capable Any other type of user device that operates in a wireless environment. The "base station" referred to below includes, but is not limited to, a Node-B, a site controller, an access point (AP), or any other type of interface device capable of operating in a wireless environment. The variables "x", "y", and "z" refer to any and interchangeable numbers that correspond to a given modulation and coding scheme, such as MCS-x, where x can take values from 1 to 9 , DAS-y, where y can take values from 5 to 12, DBS-z, where z can take values from 5 to 12.

Referring to FIG. 1, a wireless communication network (NW) 10 includes a WTRU 20, and one or more Node Bs (NBs or evolved NBs (eNBs)) 30 in cells 40. The WTRU 20 includes a processor 9 configured to implement an uncovering method for encoding a packet transmission. Each Node B 30 also has a processor 13 configured to implement an uncovering method for encoding packet transmissions.

FIG. 2 is a functional block diagram of the transceivers 110, 120. In addition to elements included in a typical transceiver, such as a WTRU or Node B, the transceivers 110, 120 also include processors 115, 125 configured to perform the methods disclosed herein; receivers 116, 126 and processor 115, 125 communications, transmitters 117, 127 are in communication with processors 115, 125; and antennas 118, 128 are in communication with receivers 116, 120 and transmitters 117, 127 to facilitate wireless Transmission and reception of data. Further, receiver 116, transmitter 117, and antenna 118 may be a single receiver, transmitter, and antenna, or may include multiple single receivers, transmitters, and antennas, respectively. Transmitter 110 may be located in the WTRU or multiple transmitters 110 may be located in the base station. Receiver 120 can be located in the WTRU or base station, or both.

Bit swapping is used for the RLC/MAC header bits, and this bit swap is considered to be a low complexity technique used on the transmitter side to reduce receiver complexity on the decoder side. Bit swapping is applied to one or more defined USF bits/symbols of the MCS-1 to MCS-4, DAS-5 to DAS-12 and DBS-5 to DBS-12 schemes, which is defined for EGPRS2 DL (REDHOT) transmission to reduce the total number of possible combinations.

One or more USF bits/symbols can be interchanged with any other location in the burst (e.g., one or more bits/symbols) carrying RLC/MAC header information (data, PAN, etc.). Since the mapping rules applied to the encoding are known in the receiver, the bit swapping can be reversed on the receiver side to reconstruct the RLC/MAC header information (data, PAN, etc.). The bit swapping process can be encoded in the transmitter and receiver as a mapping rule used in the burst formatting phase, such as "swap" (interchange) bit B_n1 relative to B_m1, bit B_n2 relative to B_m2, and so on.

All or part of the bit swap is applied to the REDHOT version of EGPRS, such as the MCS-1 to MCS-4 scheme, which uses CS-4 type USF encoding and maps to the new REDHOT Level A (RH-A), DAS-5 To the DAS-7 scheme, which uses MCS-5 to MCS-9 type USF encoding and mapping (eg EGPRS2) to other REDHOT burst type bits/symbols position.

Similar to the RH-B DBS-5 to DBS-12 encoding, all or selected subsets of USF bits encoded by the MCS-1 to MCS-4 and/or RH-A DAS-5 to DAS-7 schemes may be used. The interchange is followed by a subset of all or symbol/bit locations of the training sequence to reduce the total number of USF bit position combinations and to equally reduce WTRU implementation complexity.

The bit swapping of one or more EGPRS or new REDHOT modulation and coding schemes is applied to the currently defined bit position of the encoded USF bit, applied to another or another MCS-1 to MCS-4, DAS -5 to a selected subset of DAS-12 and/or DBS-5 to DBS-12 schemes to reduce the total number of USF mapping constellations used to map symbols/bits to bursts for REDHOT transmission .

For the following discussion, the term "N" denotes the channel coding bit obtained from the 3 USF information bits; NX (X = 1, n) is obtained from the three (3) USF information bits based on the encoding rule X. The channel coding bit; and PX (X = 1, n) is the bit position after the NX bit is to be mapped (interchanged). The value n represents the number of encoding rules. Although the following examples refer to three encoding rules, there can be any number of encoding rules such that n can represent any integer value.

USF encoding rules can be applied to specific EGPRS or EGPRS2 MCS. When the MCS is sent in the BTTI configuration, the first USF encoding rule is applied as follows: (a) how to obtain the N1 channel encoded USF bit from the three (3) USF information bits; and (b) specify which one Group bit position {P1} to map these in the bursts B0, B1, B2 and B3 of the radio block N generated bits. However, when the MCS is transmitted in the RTTI configuration, the second USF encoding rule is applied as follows: (a) how to obtain the N2 channel encoded USF bit; and (b) the bit location group {P2}. N1 and N2 may be partially the same as {P1} or {P2}. A transmitter intended to transmit a radio block configured using RTTI using a second USF encoding rule can implement the following procedure: The transmitter encodes a radio block, assuming that the radio block is transmitted in BTTI mode using the first USF encoding rule. Next, as long as N1 = N2, the transmitter swaps the bit including the bit position {P1} with the bit including the bit position {P2}. Alternatively, if the MCS is transmitted in the RTTI/BTTI hybrid configuration, the third USF encoding rule N3, {P3} is applied.

The receiver (WTRU) explicitly knows how to decode the USF in the received radio block. The RLC/MAC setup signaling indicates to the WTRU whether the received radio block is operating in BTTI, RTTI, or in RTTI/BTTI mode, and this indicates a particular USF encoding rule that must be applied by the WTRU to decode the USF. In the case mentioned above, the USF encoding rules can be the same. For example, the first USF encoding rule, the second USF encoding rule, or the third encoding rule may be the same rule.

The current subset of USF bits/symbols and/or their locations can be swapped for USF bit/symbol locations of another REDHOT or EGPRS scheme. Alternatively, the entire set of USF bits/symbols and/or their locations may be interchanged with each other for the entire set of USF bits/symbols of the EGPRS or REDHOT scheme and/or its location.

When transmitting on the REDHOT Packet Data Channel (PDCH), the USF bit/symbol location can be used with EGPRS MCS-1 to MCS-4. EGPRS MCS-5 to MCS-9 (and DAS-5 to DAS-7) are applied to each burst to perform {0, 50, 100} and second bursts from the first burst of the radio block. {34,84,98} on the top, {18,68,82} on the third plexus, and {2,52,66} on the fourth plexus to the new position {150,151,168-169 , all or a subset of 171-172, 177, 178 and 195} are interchanged. As will be apparent to those of ordinary skill in the art, sixteen (16) USF encoded bits of MCS-1 through MCS-4 can be mapped directly to these selected bit positions, or subsets of the same position. .

Alternatively, a similar simple mapping extension technique can be applied to obtain MCS-5 from three (3) USF bits or sixteen (16) USF coded bits (assuming the MCS-1 to MCS-4 scheme is used). Thirty-six (36) bits to the MCS-9.

USF bit/symbol locations {150, 151, 168-169, 171-172, 177, 178 and 195} defined by EGPRS DAS-5 to DAS-7 (currently identical to EGPRS MCS-5 to MCS-9) The USF bit/symbol position corresponding to RH-A DAS-8 to DAS-12 (i.e., three (3) symbols immediately following the training sequence) is interchanged during each burst.

The USF bit/symbol position of EGPRS MCS-1 to MCS-4 and/or DAS-5 to DAS-7 or a combination of these schemes can be interchanged with USF bits corresponding to RH-A DAS-8 to DAS-12/ Symbol position (ie three (3) symbols immediately following the training sequence). For example, when the USF bit position bits of MCS-1 to MCS-4 and DAS-5 to DAS-7 are selected to be interchanged to the USF position of the defined DAS-7 to DAS-12 scheme, two (2) are used. A different bit swapping and USF encoding bit repeat/expansion scheme.

The USF bit/symbol encoding/mapping process of one or a subset of MCS-x, DAS-y, or DBS-z can be changed to another encoding scheme or a subset of encoding schemes. For example, the number of USF coded bits of one or more MCS-x, DAS-y, or DBS-z is reduced or increased from N1 to N2 bits. This allows the USF to adjust according to at least one other MCS-x, DAS-y or DBS-z decoding scheme to reduce the number of possible (possible combinations) and decoding complexity.

Alternatively, the USF codeword generation process/encoding table of one of MCS-x, DAS-y or DBS-z or a subset thereof may be changed to a USF codeword generation process/coding table of another coding scheme to reduce The number of possible combinations of decoding.

Alternatively, a method for mapping a USF coded bit to a symbol of one or a subset of the MCS-x, DAS-y, or DBS-z scheme, using the MCS-x, DAS-y, or DBS-z scheme One other or another subset is adjusted to reduce the total number of USF configurations as a subset coding scheme or derivation, which is possible compared to the EGPRS/EGPRS2 reference format.

One or more RH-A schemes can be adjusted to the RH-B scheme. For example, QPSK-based DBS-5 and DBS-6 USF symbols/codewords are reduced to corresponding USF symbols based on 16/32QAM-based DAS-8 to DAS-12/DBS-7 to DBS-12 (or vice versa) /codeword to adjust the RH-A and RH-B schemes. The immediate benefit is that the number of mixed modulation constellations is reduced to a total of four.

In another embodiment, for a particular or selected subset of EGPRS MCS, and/or EGPRS2 DAS-x or DBS-y modulation and coding schemes, the USF bit/symbol mapping process and/or USF codeword generation is Used to The radio block is encoded as a BTTI or RTTI transmission depending on whether the BTTI and RTTI WTRU are multiplexed to the same PDCH resource. For example, if a radio block is transmitted in RTTI mode or BTTI mode or BTTI/RTTI coexistence mode, when used to encode the same radio block, to one or more MCS-x, DAS-y, and/or DBS-z schemes The USF bit/symbol mapping process and/or USF codeword generation will vary according to the reference BTTI format.

In one embodiment, the USF bit/symbol coding scheme and/or the USF codeword generation table for one or more MCS-x, DAS-y, or DBS-z is based on another scheme (eg, MCS-x, DAS) -y or DBS-z). For example, the burst-wise portion of the USF code table or all or part of the deterministic mapping rule is repeated, all of which are equivalent and can be used to implement this process in the transmitter and receiver.

The WTRU implements this process based on configuration messages received from the network, such as Temporary Block Flow (TBF) DL allocations and the like, as will be apparent to those of ordinary skill in the art, based on the Packet Data Channel (PDCH). Whether assigned to EGPRS operation or REDHOT operation, the receiver is configured to decode legacy EGPRS MCS-1 to MCS-4. In the first case, EGPRS bursts use traditional methods for reception and processing. In the second case, the WTRU configures its decoder to account for the existence of any USF decoding technique, such as bit swapping, extensions on USF bits/symbols, etc., as described above.

It will be apparent to those of ordinary skill in the art that bitwise interchange is applied to USF bits in MCS-1 to MCS-4, DAS-5 to DAS-12, and DBS-5 to DBS-12/ Symbol to reduce possible combinations The method of the total number can be extended or independently applied while allowing the GERAN delay reduction (LATRED) in R7, that is, considering the possibility of RTI-A or RH-B RTTI operation.

An EGPRS2 WTRU operating in BTTI mode may decode a USF from a first RTTI transmission, which may use a modulation type/set of EGPRS or EGPRS2 modulation and coding schemes, the EGPRS or EGPRS2 modulation and coding scheme The modulation type/set is different from the second RTTI transmission during the BTTI time period on one or more allocation time slots. Figure 7B shows a comparison of this embodiment with the prior art in Figure 7A. Four frames (N to N+3) are shown in Figure 7B, and each frame includes two time slots (TS2 and two (2) of the four (4) bursts that make up the radio block. TS3). In Figure 7A, each of the four (4) constituting the entire radio block must have the same modulation type, such that the first frame of the RTTI transmission includes the first two (2) bursts and includes The last two (2) bursts of the second frame have the same modulation type.

As shown in FIG. 7B, the frame including the first two (2) bursts of the RTTI transmission and the frame including the last two (2) bursts may have different modulation types. In this case, when the modulation type of the two frames is different from the modulation type of the last two frames, WTRU1 retrieves the USF from the four bursts. In this example, for purposes of illustration, first frame 720 and second frame 730 are encoded using 8PSK modulation, while third frame 740 and fourth frame 750 are encoded using 16QAM. By processing all four bursts, WTRUl is able to properly decode the USF.

Another embodiment of the USF decoding process is shown in FIG. in 1000, the WTRU (or other receiving device) receives four (4) bursts on the time slot allocated by the BTTI interval. The modulation type (type 1) of the first two (2) bursts is determined at 1010. The modulation type (type 2) of the last two (2) bursts is determined at 1020. Alternatively, the modulation type of one or more received bursts in the first group can be determined while the WTRU is still receiving or processing one or more bursts in the second group.

The modulation types (Type 1 and Type 2) are compared at 1030, and if they are the same, the USF and RLC/MAC are decoded at 1040. If the USF is an assigned USF of 1050, then the data can be transmitted on the uplink channel. If the USF is not the assigned USF, then the WTRU is waiting for another four (4) bursts at 1000.

If the modulation type is not the same at 1030, then at 1080 it is determined whether a particular modulation combination (type 1 and type 2 combination) is allowed. If so, the USF decodes at 1110. Then, at 1050, the decoded USF is compared to the assigned USF, and if they are the same, the data can be transmitted on the uplink channel. If the USF is not the assigned USF, then the WTRU is waiting for another four (4) bursts at 1000.

If the modulation combination at 1080 is not allowed, the decoding fails and the WTRU waits for another four (4) bursts at 1000.

Alternatively, the allowable modulation type in the first and second RTTI intervals (or an allowable subset from MCS-x, DAS-y, DBS-z in an equivalent manner) is not limited. In this case, the receiver proceeds to the USF decoding step in 1110.

In another embodiment, the first and second RTTI intervals are acceptable The type of modulation (or the selection of an allowable subset from MCS-x, DAS-y, DBS-z in an equivalent manner) is limited. The limitation may be based on a selection of a modulation type (or a subset of MCS-x, DAS-y, DBS-z) in the first or second RTTI interval during the BTTI interval to reduce the amount of processing that the receiver must process in order to decode the USF. The number of possible combinations. An exemplary flow chart of this embodiment is shown in FIG. At 820, a first modulation type of the first RTTI interval is detected. At 860, the receiver (Rx) is configured to detect an allowable modulation type on the second RTTI interval. At 870, the USF is retrieved. At 880, the USF is decoded. Then at 882, the decoded USF is compared to the assigned USF, and if they are equal (same), the material can be transmitted in the uplink (UL) 890, otherwise detection 820, configuration 860, capture 870, and decode 880 Repeated.

The restrictions for one or more given modulation types (GMSK, 8PSK, QPSK, 16QAM, 32QAM) are equivalent to the restrictions for a particular selected subset of MCS, DAS, and/or DBS modulation and coding schemes. For example, the restriction on the modulation type of only GMSK is equivalent to allowing only CS-1 to CS-4 and MCS-1 to MCS-4. Modulation type 8PSK includes MCS-5 to MCS-9 and DAS-5 to DAS-7. Modulation type 32QAM includes DAS-10 to DAS-12 and DBS-10 to DBS-12.

The possible modulation types or limitations of the subset of modulation and coding schemes may be given by rules implemented on the network, the WTRU, or both, where the modulation and coding scheme may occur at the first or second RTTI Interval (or selected subset of MCS-x, DAS-y, DBS-z). The limitation of the possible combination of the second RTTI interval occurs according to the previous first RTTI interval The modulation type or the subset of modulation and coding schemes. Alternatively, the possible combination of the first RTTI interval is limited by the modulation type or subset of the EGPRS or EGPRS2 modulation and coding scheme that occurs during the second RTTI interval (the lower RTTI interval). Alternatively, the restriction is applied to a subset of allowable modulation types or modulation and coding schemes for the first and second RTTI intervals. Preferably, the restriction rules are fixed and are known to both the WTRU and the network. Alternatively, the restriction rules may be configured by signaling, such as an RLC/MAC message for establishing a radio link, a TBF, or allocating radio resources as an example.

Moreover, the possible modulation types or EPON or EGPRS2 modulation and coding scheme subsets that can follow each other in subsequent RTTI intervals can be based on a set of capabilities supported by a particular WTRU. Since the RH-A WTRU is not required to decode the USF from the RH-B DBS-z scheme, the RH-A WTRU may use a different set of restrictions than the RH-B WTRU (which requires decoding a larger number of combinations). When two (2) partial code words of different modulation types are paired, the restrictions imposed on the (sub)set of allowable modulation types or EGPRS or EGPRS2 modulation and coding schemes may be selected as USF The function of the codeword and its minimum Hamming distance to eliminate and exclude specific pathologic conditions (small Hamming distance between perceived codeword combinations at isolated points) to improve USF detection in normal situations performance.

The table below shows an example of such a restriction on a (sub)set of allowable modulation types or EGPRS or EGPRS2 modulation and coding schemes. This particular example gives the allowed in the second RTTI interval (lateral) The second RTTI interval (lateral) is a function of the modulation type used on the first RTTI interval (longitudinal) relative to the list of disallowed modulation types. This illustrative example represents only one possible compromise and can be extended to other possible tradeoffs between the reduction in throughput compared to the general case versus the decoding simplification (where in principle any modulation type can follow other anyone).

Figure 9 shows a flow diagram of an embodiment of such an exemplary limitation (and also a description of the process occurring in detection 820 in Figure 8). A first RTTI up-variable type of detection 820 is initiated at 824, where the first RTTI interval is tested to determine if it is a GMSK modulation. If the determination is affirmative, then at 826, the second RTTI interval can be any of the following modulation types: GMSK, 8PSK, 16QAM, or 32QAM. If not, then at 828, the first RTTI interval is similarly tested to determine if it is 8PSK. If the determination is affirmative, then at 830, the second RTTI interval can be any of the following modulation types: GMSK, 8PSK, or QPSK. Otherwise at 832, the process continues to test the first RTTI interval to determine if it is QPSK. If the determination is affirmative, then at 834, the second RTTI interval can be any of the following modulation types: 8PSK, QPSK, 16QAM, or 32QAM. Otherwise, the process continues at 836 to test the first RTTI interval to determine if it is 16QAM. If the determination is affirmative, then at 838, the second RTTI interval can be any of the following modulation types: GMSK, QPSK, 16QAM, or 32QAM. Otherwise, at 840 the process continues to test the first RTTI interval to determine if it is 32QAM. If the determination is affirmative, then at 842, the second RTTI interval can be of all types. Next, the modulation type on the second RTTI is detected at 844 and tested in 846 to determine if it is an allowed modulation type. If the determination is affirmative, the USF is decoded at 848 and the data can be subsequently transmitted on the uplink. Otherwise, the USF is not decoded at 850 and no data is transmitted. In other cases, the process waits for the next RTTI interval (data transfer).

There may be more than one set of restriction rules that are used in the system (equivalent to the modulation type conversion allowed between the first RTTI and the second RTTI interval). The restriction rule may be based on the type and capability of the WTRU on the multiplex to a particular PDCH resource. In the case of a single restriction rule or the existence of a set of restriction rules (multiple rules), these restriction rules may be signaled to the WTRU during the TBF/resource establishment/distribution phase, or similarly via EGPRS RLC/MAC signaling messages. Extended to convey, or given by fixed rules implemented in the WTRU and/or the network. This can include messages such as packet downlink allocation, multi-TBF downlink allocation, and packet uplink. Provisioning, multi-TBF uplink allocation, packet reconfiguration at the time of packet, multi-TBF time slot reconfiguration, or packet CS release indication message.

In another embodiment, different stealing flag settings may be applied to EGPRS2 transmission of one or a selected subset of EGPRS or EGPRS2 MCS-x, DAS-y and/or DBS-z to assist the receiver Determining the correct USF decoding format, the order of radio blocks in RTTI or BTTI or hybrid RTTI/BTTI intervals, or whether the USF encoding format changes, or one or more bursts or received, compared to a reference encoding situation such as BTTI transmission Whether the radio block belongs to the first or second RTTI interval in the BTTI interval (where different settings for some burst portions can be applied last). This may include an RTTI USF mode indication with/without BTTI coexistence (whether or not this feature is supported). For example, a configuration of one or more different stealing flags for EGPRS2 MCS-x, DAS-y, and/or DBS-z radio blocks (or per time period) can be used to indicate one or more of the following: the correct USF format is Perform relative decoding and help the receiver determine the correct USF decoding format to test the received one or more bursts, radio blocks, etc., USF sent in BTTI configuration, USF sent in RTTI configuration, coexistence using BTTI The mode transmits the USF in the RTTI configuration and corresponds to the first radio block received in the BTTI interval relative to the second RTTI interval.

For purposes of illustration, and without loss of versatility, the stealing flag can be set as follows in the DAS-8/9 case in the first/second consecutive RTTI interval of the DAS-8/9:

The particular value selected to indicate a given stealing flag codeword for a particular USF mode may be any particular value as long as the value is unique relative to the indicated context/mode.

For different sets of EGPRS2 MCS-x, DAS-y and/or DBS-z modulation and coding schemes, a clear vanishing flag configuration can be used.

There are many different and equivalent ways to adjust the USF encoding and position mapping of USF bits/symbols in MCS-1 to MCS-4, DAS-5 to DAS-12, DBS-5 to DBS-12 to reduce and adjust They are thus used for different burst types in WTRU implementations.

Although the features and elements of the present invention are described in a particular combination, each feature or element can be used alone or in combination with other features and elements. . The methods or flow diagrams provided herein can be implemented in a computer program, software or firmware executed by a general purpose computer or processor. Examples of computer readable storage media include magnetic memory such as read only memory (ROM), random access memory (RAM), scratchpad, buffer memory, semiconductor memory device, internal hard disk, and removable magnetic disk. Media, magneto-optical media, and CD-ROM Optical media such as magnetic sheets and digital versatile discs (DVDs).

Suitable processors, for example, include: general purpose processors, special purpose processors, conventional processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, Controller, microcontroller, dedicated integrated circuit (ASIC), field programmable gate array (FPGA) circuit, any integrated circuit (IC) and/or state machine.

A processor associated with the software can be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host computer Use it. The WTRU can be used in conjunction with modules implemented in hardware and/or software, such as cameras, camera modules, video phones, speaker phones, vibrators, speakers, microphones, TV transceivers, hands-free headsets, keyboards, Bluetooth® Module, frequency modulation (FM) wireless unit, liquid crystal display (LCD) display unit, organic light emitting diode (OLED) display unit, digital music player, media player, video game machine module, internet browser and / or any wireless local area network (WLAN) or ultra-wideband (UWB) module.

9, 13‧‧‧ processor

10‧‧‧Wireless Communication Network (NW)

20‧‧‧Wireless Transmitting/Receiving Unit (WTRU)

30‧‧‧Evolved Node B (Enb)

40‧‧‧cell

110, 120‧‧‧ transceiver

115, 125‧‧‧ processor

116, 126‧‧‧ Receiver

117, 127‧‧‧ transmitter

118, 128‧‧‧ antenna

USF‧‧‧Uplink Status Flag

TS‧‧‧ slot

RTTI‧‧‧ Reduced transmission time interval

BTTI‧‧‧Basic transmission time interval

The invention can be understood in more detail from the following description, which is given by way of example in conjunction with the drawings, wherein: FIG. 1 is an example of a 3GPP wireless communication system; FIG. 2 illustrates two transceivers, for example Functional block diagram of an exemplary WTRU and Node B (or evolved Node B); Figure 3 shows the burst map of the USF sent in 20ms; Figure 4 shows MCS-5 and MCS-6 Cluster mapping; Figure 5 shows the burst mapping of MCS-7, MCS-8, and MCS-9; Figure 6 shows the USF in the RED HOT B (DBS-5 to DBS-12) case. Crowd mapping.

Figure 7A compares a prior art single modulation decoding technique with one embodiment shown in Figure 7B, which is capable of processing and decoding different modulation types; Figure 8 is a flow diagram of an exemplary USF decoding process FIG. 9 shows an embodiment for determining a modulation type; and FIG. 10 shows an embodiment of a decoding process for an EGPRS WTRU operating in a BTTI mode.

USF‧‧‧Uplink Status Flag

Claims (8)

A method for use in a base station for a reduced transmission time interval between a second half of a basic transmission time interval (BTTI) period and a first half of the BTTI period ( RTTI) time slot pair transmitting a data, the method comprising: encoding a first block using a first modulation and coding scheme (MCS); in the first half of the basic transmission time interval (BTTI) period Transmitting the encoded first block to a wireless transmit/receive unit (WTRU) on the RTTI slot pair; determining to allow a subset of MCS for a second block as a function of the first MCS; The MCS subset determines a second MCS for encoding the second block; encoding the second block using the second MCS; and transmitting the quilt on the slot pair in the RTTI in the second half of the BTTI period The second block of coding. The method of claim 1, wherein the second MCS is determined based on a flux characteristic of the first MCS. The method of claim 1, wherein transmitting the encoded first block or transmitting the encoded second block is via a GSM Enhanced Data Rate Global Evolution (EDGE) Radio Access Network (GERAN) Access the network to execute. The method of claim 1, wherein a modulation pattern associated with the first MCS or the second MCS is Gaussian Minimum Shift Keying (GMSK), 8 Phase Shift Keying (8PSK) One of orthogonal PSK (QPSK), 16 quadrature amplitude modulation (16QAM), and 32QAM modulation. A base station configured to be a reduced transmission time interval (RTTI) slot pair on a second half of a basic transmission time interval (BTTI) period and a first half of the BTTI period Transmitting a data, the base station includes: a transceiver configured to: encode a first block using a first modulation and coding scheme (MCS), and encode a second block using a second MCS Transmitting the encoded first block to a wireless transmit/receive unit (WTRU) on the RTTI time slot pair in the first half of the basic transmission time interval (BTTI), and one of the BTTI periods An RTTI time slot pair in the second half transmits the encoded second block to the WTRU; and a processor configured to determine an MCS subset allowed for the second block as the first A function of the MCS, and determining the second MCS from the subset of MCS for encoding the second block. The base station of claim 5, wherein the second MCS is determined based on a flow characteristic of the first MCS. The base station of claim 5, wherein the transceiver is configured to transmit the encoded first through a GSM Enhanced Data Rate Global Evolution (EDGE) Radio Access Network (GERAN) access network One or the second block to be encoded. The base station according to claim 5, wherein a modulation type associated with the first MCS or the second MCS is Gaussian Minimum Shift Keying (GMSK) and 8-phase shift keying (8PSK). One of orthogonal PSK (QPSK), 16 quadrature amplitude modulation (16QAM), and 32QAM modulation.